Challenges in economic valuation of wetland protection under climate change impacts

Resumo

The conservation of humid lands emerges as a priority within the social debate. Given the contribution of wetlands to sustain human well-being, their protection in the face of increasing anthropogenic stresses is perceived as socially desirable. This is especially true in the face of climate change (CC), which is expected to become the major source of wetlands’ deterioration in the future. In this sense, to be welfare-maximizing, policy design should be guided by knowledge about the valuation of the social benefits of wetlands’ protection. In this framework, while the valuation task becomes a crucial tool to better inform policymakers, it is also associated with some challenges. These are due to the fact that CC is a future time-persistent problem and its impacts are expected to be complex, inherently uncertain and extended over the long- and very long-term. Regardless of the fact that these aspects are anticipated to affect social welfare, their role in stated preference valuation has been largely underexplored. To shed some light on these issues, three are the research questions addressed in this thesis. First, the trade-offs between the social value of avoiding different and complex wetland impacts. Second, the effect on the social preferences for preservation measures of incorporating information about the inherent uncertainty of environmental processes. Third, the role of sustainability issues by examining whether social preferences for policies having their benefits in the long- and very long-term are non-declining. To answer these questions, a choice experiment has been undertaken in S’Albufera wetland (Mallorca, Spain). In specific, the valuation exercise has been designed to consider: separate attributes for the complex impacts of CC, alternative scenarios of probability of impacts’ occurrence to express inherent uncertainty and different time horizons in the long- and very long-term. Results have shown that complexity, inherent uncertainty and sustainability issues are relevant aspects. Individuals overall care about the impacts of CC on wetlands, even though they assign unequal values to the different impacts considered, suggesting substitution and complementarity patterns that are useful for the design of environmental policies. Respondents are sensitive to the inherent uncertainty associated with the natural variability of CC effects. They also care about sustainability issues, by equally valuing preservation in the long-term and very long-term, due to a concern for the well-being of future generations. These findings are important not only to better inform wetland management under CC, but also to guide stated preference valuation practitioners. Indeed, results show that the challenges associated with valuation in the face of time-persistent environmental problems, like CC, need to be carefully considered, given that ignoring them can have important social welfare implications.